Understanding the mechanisms mediating learning and other forms of cortical plasticity at the level of neuronal ensembles could aid in the development of therapies for neurodegenerative disease as well as the design of assistive brain-computer interfaces. However, the relationship between neuronal ensemble activity and the kinetics of cortical neurotransmitter release and clearance are poorly understood. Rodent experiments have highlighted the role of neuromodulators, such as dopamine, in cortical plasticity and learning. Neuromodulators simultaneously engage large numbers of neurons, but their effects on neuronal ensemble activity cannot be readily observed directly. For example, conventional approaches may allow for recording of electrical transmission or stimulation data, but such data does not provide a full picture as chemical sensing and delivery data may be omitted. Conversely, observation along the chemical domain may not allow for obtaining the corresponding electrical data. Using conventional approaches, simultaneous acquisition of such multi-modal data in the site corresponding in size to a neuron or groups of neurons is not feasible.